Tomcat - Types of deployment
The deployment staging mode determines how deployment fi les are made available
to the target servers that must deploy an application or standalone module. The
Tomcat 7 server provides three different options for staging fi les listed as follows:
- Stage mode
- Nostage mode
- External_stage mode
The following table describes the behavior and best practices for using the different
deployment staging modes:
| Deployment
Staging
Mode | Behavior | When to Use |
| Stage | The Tomcat administrator
fi rst copies the deployment
unit source fi les to the staging
directories of the target servers
and then the target servers
deploy them using their local
copy of the deployment fi les. | Deploying small or moderate-sized
applications to multiple Tomcat 7
server instances.
Deploying small or moderate-sized
applications to a cluster. |
| Nostage | The Tomcat administrator does
not copy the deployment unit
fi les. Instead, all servers deploy
using the same physical copy
of the deployment fi les, which
must be directly accessible by
the Tomcat administrator and
target servers.
Nostage deployments of
exploded archive directories is
not recommended | Deploying to a single server
instance.
Deploying to a cluster on a multihomed
machine.
Deploying very large applications
to multiple targets or to a cluster
where deployment fi les are placed
on the server. |
| External_stage | The Tomcat administrator
does not copy the deployment
fi les. Instead, the administrator
must ensure that deployment
fi les are distributed to the
correct staging directory
location before deployment (for
example, by manually copying
fi les prior to deployment).
With external_stage
deployments, the Tomcat
administrator requires a copy
of the deployment fi les for
validation purposes. Copies of
the deployment fi les that reside
in the target servers' staging
directories are not validated
before deployment. | Deployments where you want to
manually control the distribution
of deployment fi les to the target
servers.
Deploying to the server instance
where third-party applications
or scripts manage the copying of
deployment fi les to the correct
staging directories.
Deployments that do not require
a dynamic update of selected
deployment descriptors via the
Tomcat Manager (not supported in
external_stage mode).
Deployments that do not require
partial redeployment of the
application components. |
